Polypropylene compositions of improved dyeability and process of dyeing



United States Patent @fifice 3,163,492 Patented Dec. 29, 1964 3,163,492 POLYPROPYLENE COMPOSITIQNS OF MPRQVED DYEABILITY AND PRQCESS F DYEWG Walter W. Thomas, Wilmington, Deb, assignor to Hercules Powder Company, Wilmington, Del, a corporation of Delaware No Drawing. Filed July 23, 1962, Ser. No. 211,859 13 Claims. (Cl. 8-55) This invention relates to stereoregular polypropylene fibers of improved dyeability and to a process for improving the dyeability of stereoregular polypropylene fibers.

One of the new fibers that has been introduced recently to trade is made from stereoregular polypropylene, a highly crystalline polymer that melts in the range of about 165 C. to about 172 C. Stereoregular polypropylene filamentary articles have potentially wide application in textiles, since they posses excellent physical properties, such as, for example, excellent tenacities, superior fatique and abrasion resistance, and the like. In order for stereoregular polypropylene filamentary articles to enjoy widespread use, however, it is desirable that such articles be dyeable in deep shades in a wide range of colors which are reasonably color fast when subjected to Washing and to dry cleaning treatments, and are also reasonably stable to light.

The dyeing of stereoregular polypropylene fiber, however, has been recognized as an especially diflicult problem, even more so than with other known synthetic fiber materials, because of the extremely hydrophobic nature of stereoregular polypropylene and the absence of functional groups in its structure which can serve as dye sites to enable dyestuffs to become firmly attached to the fibers. As a consequence, dyeing methods and dyestufi's developed for other materials of a hydrophobic nature have proven to be deficient for dyeing stereoregular polypropylene fibers.

While considerable progress has been made in discovering suitable methods for dyeing stereoregular polypropylene fibers, the fact remains that such fibers can be dyed in medium to deep shades only a few selected dyestuiis, and the light fastness of these is only marginal. In many cases it has been possible to dye stereoregular polypropylene fibers in light to medium shades only, even with the new methods which have been devised. There is a real need, therefore, for means whereby stereoregular polypropylene fibers can be dyed to deep shades of improved light fastness in-a wide range of colors.

It is an object of the present invention, therefore, to provide artificial fibers of improved dyeability having a basis of stereoregular polypropylene.

Another object of this invention is to provide a process for improving the dyeability of artificial fibers having a basis of stereoregular polypropylene so that such fibers can be dyed to deep shades of improved light fastness in a wide range of colors. Other objects and advantages of this invention will appear from the following description.

In accordance with this invention it has been discovered that artificial fibers consisting essentially of a uniform admixture of stereoregular polypropylene and from about 1% to about 25 preferably from about 1% to about 10%, by weight of said admixture, of a copolymer of ethylene and an ethylenically unsaturated ester of a saturated fatty acid can be dyed to a depth of shade Which is enhanced twoto threefold in comparison to dyeings of fibers of unmodified stereoregular polypropylene, and the light fastness of these dyeings may also be enhanced by a factor of twoto threefold over similar dyeings of fibers of unmodified stereoregu-lar polypropylene. This enhancement of both color depth and light fastness of dyeings in accordance with this invention is obtainable with any dyestuli which will dye stereoregular polypropylene fiber, and includes those dyes which fully penetrate the fiber as well as those dyes which penetrate the fiber only superficially to produce ring dyeings of the fiber.

In preferred embodiments the artificial fibers of this invention consist essentially of a uniform admixture of stereoregular polypropylene, from about 1% to about 25% by weight of said admixture of a copolymer of ethylene and an ethylenically unsaturated ester of a saturated fatty acid and from about 0.01% to about 5% by weight of said polypropylene of a polyvalent metal in the form of a finely dispersed or dissolved polyvalent metal compound uniformly distributed therein. Fibers based on these preferred admixtures, when dyed with dyestuffs which can form complexes with polyvalent metals atoms of said polyvalent metal compound, generally show greatly improved resistance to loss of color or fading by light, and may also show improved resistance to loss of color when subjected to dry cleaning treatment.

The uniform admixtures of stereoregular polypropylene and copolymer of ethylene and an ethylenically unsaturated ester of a saturated fatty acid, with or without polyvalent metal compound, from which the artificial fibers of improved dyeability of this invention are prepared are hereinafter termed alloys, since they are intimate physical mixtures or blends of the copolymer of ethylene and an unsaturated ester of a saturated fatty acid with or without polyvalent metal compound, uniformly distributed through the body of the stereoregular polypropylene.

The process for improving the dyeability of stereo regular polypropylene filamentary material in accordance with this invention, therefore, comprises preparing an alloy of stereoregular polypropylene with from about 1% to about 25% by weight of said alloy of a copoylmer of ethylene and an ethylenically unsaturated ester of a saturated fatty acid, forming the alloy into filamentary material, and dyeing the filamentary material.

In preferred embodiments of the invention the process for improving dyeability of stereoregular polypropylene filamentary material comprises preparing an alloy of stereoregular polypropylene with from about 1% to about 25% by weight of said alloy of a copolymer of ethylene and an ethylenically unsaturated ester of a saturated fatty acid, and with from about 0.01% to about 5% by weight of said polypropylene of a polyvalent metal in the form of a polyvalent metal compound, forming the alloy into filamentary material, and dyeing the filamentary material with a dyestuif which is capable of forming complexes with polyvalent metal atoms of said polyvalent metal compound.

The alloys of this invention are readily prepared by conventional methods of mixing and blending employed in tl e plastics art. For example, stereoregular polypropylene flake or molding powder granules, and particles or granules of a copolymer of ethylene and an ethylenically unsaturated ester of a saturated fatty acid may be preliminarily mixed together in a tumbling barrel, or in a Sweetie barrel, or in a ribbon mixer, or the like, and the resulting mixture may then be intimately blended by malaxating on a hot two-roll mill, or in a Banbury mixer, or in the barrel of a heated extruding apparatus to prepare the desired alloy which may then be directly melt spun into filaments, or reduced to suitable granules by conventional comminuting methods for charging to a melt spinning or static spinning apparatus, or for dis solving in a suitable solvent for solvent spinning.

The alloys of this invention may also be conveniently prepared by applying a solution of a copolymer of ethylene and an ethylenically unsaturated ester of a saturated fatty acid in a volatile solvent such as chloroform, methylene chloride, toluene, or the like, by spraying, mixing, or the like, to the surfaces of stereoregular polypropylene flake or molding powder granules, evaporating the volatile solvent, and then malaxating the thus coated stereoregular polypropylene particles as set forth above to intimately blend the applied copolymer uniformly with the stereoregular polypropylene to form the desired alloy.

The polyvalent metal compound of preferred embodiments of this invention may be incorporated into the alloy at the same time and by the same means that the copolymer of ethylene and ethylenically unsaturated ester of saturated fatty acid is incorporated thereinto. If desired, however, the polyvalent metal compound may be introduced into the stereoregular polypropylene at any convenient point in the manufacture thereof prior to preparation of the alloy. For example, the polyvalent metal compound can be added to the propylene polymerization reaction mixture, or can be incorporated into stereoregular polypropylene flake or granules by the same or similar conventional methods of mixing and blending as set forth above for preparing the alloys of this invention.

The stereoregular polypropylene employed in this invention is a standard article of commerce, often called isotactic polypropylene. The polymer can, and normally will, contain ingredients other than those specified in this invention. Such other ingredients include, by way of example, antacids, such as calcium stearate, antioxidants and heat stabilizers such as alkylated phenols, alkylidene bis(alkyl phenols), terpene phenols, polyhydroxy chromans, alkyl esters of thiodipropionic acid, and the like. They may also include light stabilizers such as benzophenone derivatives and alkyl and aralkyl esters of salicylic acid.

The copolymers of ethylene and ethylenically unsaturated ester of saturated fatty acid which are suitable for preparation of the alloys of this invention are essentially amorphous high molecular weight solid resins having a weight ratio of ethylene to ethylenically unsaturated ester of saturated fatty acid between about 15:85 and 85:15, and preferably between about 50:50 and 80:20, and a melt index, according to ASTM procedure D-1238- 57T, of about 2 to about 30, and preferably about to about 30. These copolymers can be prepared by copolymerizing a mixture of ethylene and the ethylenically unsaturated ester of saturated fatty acid using catalysts and conditions known to the art. Suitable methods are disclosed in U.S. 2,200,429; U.S. 2,394,960; U.S. 2,395,381; and U.S. 2,703,794.

The ethylenically unsaturated esters of saturated fatty acids which are copolymerized with ethylene in accordance with this invention have the general formula RCOOR' in which R is selected from the group consisting of hydrogen and straight or branched chain alkyl radicals and R is an alkenyl radical having a terminal CH :C group. Suitable alkyl radicals are those containing from 1 to about 18 carbon atoms, and preferably from 1 to about 6 carbon atoms, and include by way of example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, and straight and branched chain amyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, octadecyl, and the like, radicals. Suitable alkenyl radicals are those having from 2 to about 12 carbon atoms, and preferably from 2 to about 6 carbon atoms, and include by way of example, vinyl, allyl, isopropenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, and dodecenyl' radicals having a terminal CH =C group. Illustrative of typical ethylenically unsaturated esters of saturated fatty acids suitable for the purposes of this invention are vinyl formate, vinyl acetate, vinyl propionate, allyl acetate, allyl propionate, isopropenyl butyrate, hexenyl acetate, pentenyl hexanoate, allyl octanoate, nonenyl pentanoate, decenyl acetate, vinyl decanoate, propenyl undecanoate, vinyl dodecanoate, do-

decenyl propionate, vinyl stearate, and the like. Copolymers of ethylene and vinyl acetate are presently preferred, since these are readily available commercially.

The amount of copolymer of ethylene and ethylenically unsaturated ester of saturated fatty acid that is alloyed with the stereoregular polypropylene is determined somewhat by the particular alloying copolymer employed, but in any case is sufficient to accomplish the purposes of this invention without producing any appreciable adverse effect on the strength or flexibility properties of the fiber produced from the alloy, and in general is between about 1% and about 25% by weight of the alloy, preferably between about 1% and 10%. An amount below about 1% by weight of alloying copolymer is generally insufiicient to appreciably enhance the dyeability 0f the fiber produced from the alloy. The upper limit is just short of an amount which can cause incipient phase separation, or melt fracture in the spinning melt, since such phase separation can cause imperfections leading to loss of strength or embrittlement in the fiber produced therefrom.

Any polyvalent metal compound that releases its metal atoms for chelation or formation of complexes with dye molecules which can form such complexes is suitable for the purposes of this invention. Accordingly, suitable polyvalent metal compounds may be inorganic or organic in nature, as for example, inorganic salts, organic salts, or organo-metallic compounds. Typical polyvalent metal compounds include, by way of example, compounds of copper, zinc, calcium, magnesium, strontium, barium, cadmium, aluminum, titanium, tin, lead, vanadium, antimony, bismuth, chromium, molybdenum, manganese, iron, cobalt, nickel, and the like; such as the halides, nitrates, sulfates, carbonates, bicarbonates, phosphates, stannates, chromates, dichromates, and the like; salts of'organic acids such as the formates, acetates, butyrates, octanoates, laurates, oleates, stearates, benzoates, phthalates, oxalates, tartr-ates, citrates, malonates, maleates, sebacates, and the like; and organo-metallic compounds such as nickel-, cobalt-, iron-, manganese carbonyls; alkylaluminum, alkylmagnesium, alkylzinc, alkyllead; nickel and chromium phenolphenolates; chelates of nickel, chromium, cobalt, aluminum, zinc, and the like with acetylacetone, trifluoroacetylacetone, acetonylacetone, benzoylacetone, furoylacetone, dibenzoylmethane, acetoacetic acid, ethyl acetoacetate, formylacetone, hydroxyethyl methyl acetone, hydroxyacetone, o-hydroxyacetophenone, 2,5- dihydroxy-p-benzophenone, salicyaldehyde, ethyl glycolate, 2-hydroxyethyl acetate, monoesters of oxalic acid, monoand diesters of malonic acid, malonaldehyde, ethoxyacetic acid, 2,3-butanedione-monoxime, glyoxal monoxime, N-phenyl benzohydroxamic acid, dimethyl glyoxime, 1,3-nitroalcohols, 1,3-nitroketones, 2-nitroacetic acid, 1,2-nitrosooximes, various amino hydroxy structures, such as for example, amino acetic acid, anthranilic acid, S-hydroxy quinoline, salicylimide, o-amino phenols, amino enols such as derived from amino anthraquinone and amino naphthoquinones and from ether and ester derivatives of these by hydrolysis, and the like; and any desired mixture of any of the above or equivalent polyvalent metal compounds. In general, organic salts of polyvalent metals and organo-metallic compounds are preferred, since these compounds are more compatible with the alloys of this invention and release their metal atoms more readily for formation of complexes with dyestuffs which are capable of forming such complexes, as for example, dibutyl tin dilaurate, chromium acetate, nickel phenol-phenolate or bis(p-tetramethylbutylphenol) sulfide (containing 6.1% nickel), bis(1-[2-hydroxyethyl]-2- undecyl-2-imidazoline) chromium acetate (containing 6.7% chromium), (l-[2-hydroxyethyl1-2-undecyl-2- imidazoline) chromium acetate (containing 11% chromium), nickel phenolate of di(2-hydroxy-5-[1,1,3,3-tetramethyl butyl] phenyl) sulfone, and the like.

The amountof such polyvalent metalin theform" of a polyvalent metal compounduniformly distributedithere, in can rangefromvery-small amounts on theorder of 0.01% by weight based'onaweightof stereoregular polypropylene employed, in the alloys; to amounts on the order of 5% or more,.pre ferably between about 0.01% andab,out 2% by weightjbasedon-weightof stereoregu lar polypropylene employed 5' in t the; alloys The: polya valent-metaladye molecule-complexes formed inaccordance with this. invention may becomplexes injwhich, one metal .atom is complexed. with one. dye molecule, or complexes in which one'; metal atom iscomplexed with two dye molecules, or:may be a' mixture ofiboth types; More over, it has beenfound that polyvalent metalatoms-such as. nickel or chromium in organo-metallic, compounds whichare .added to stereoregular. polypropylene to stabilize the same against the degrading eifect oflight may also form insoluble. stable complexes-with dye molecules which are: capable ofiforming such complexes. Inthis latter case, sufiicient=polyvalentmetal compoundis used to provide for bothstabilizationof-the alloy fibers and formation of insoluble stable complexes withathe dyemolecules.

Forrning of'the'alloys of this invention-into filamentary material is readily accomplished by. any. of. the. conven-v tional spinning, knitting and weaving procedures well known in the art, employing customaryand well known lubricating, finishing, delustering, brightening,.antistatic. agents, \and'the like. If desired, minor:amounts, on the order of 1%v or less, of; various conventional. internal lubricating agents, antistatic agents, inorganic or organic delustering agents, optical brightening agents,- and: the like, may be incorporatediinto the alloyv compositions of this invention. prior to formation into filamentary material. The alloys, obviously, are. initially formedinto continuous filaments, either by solution spinning or by melt spinning, preferably by meltspinning. Typical melt extrusion conditions for the alloys, of this invention are as .follows:

The continuous filaments thus produced may be employed as such forfurther processing into y arns,, threa ds, cords, and the like for knitting or: weaving of textile fabric, or may becut into'staplefiber for-:such' further processing.

Artificial fibers prepared. from the alloys of this invention can be dyed in the form of continuous; filaments or staple fiber, or yarns, threads, cords, etc., produced from such filaments: or staple. fiber,,as well as. fabric.

knitted or woven therefrom. Prior-to dyeing, the filamentary material is givenna conventional scouring treatment in an aqueousdetergent or-soapbath to remove residual spinning and. weaving lubricants andsizing agents. For example, the filamentary material may be scoured at about a 40 to llliquor/fiber ratio by weight in an aqueous bath containing -from-about"l to about; 2%

by weight, based on fiber weight, ofa nonionic detergent such as the alkylphenoxypoly(ethyleneoxy) ethanol type (Igepal C0630 or Triton X-lOO), or an anionic detergent such as'the-higher alkyl benzene sulfonatetype, and adjustedtoa pH of about 7 m9 with soda ash or. tetrasodium pyrophosphate, for about 30' minutes: at 160180 F. The scouredfilamentary material'is-then well rinsed andkept' damp fordyeing.

Iheisame dyesand dyeing procedures awhichzhave been foundauseful fondyeing stereoregular polypropylene fiber are suitable-for: dyeingsthe alloy. fibers-:of-athisinvention. In; general; these;- useful: dyes 5 fall; into ifivezmainz classes; or types as follows: namely; dispersedyes; azoic. dyes; .vat dyes,- vat esterrdyes; andrsulfur-dyes: These are .allwell known; dye 5113/1133, and a; substantial listing: of: individual dyes: of;eaehstyperappearsnn she-Technical .Manual [of the American Association of Textile Chemists. andColorists (AATGC); VolumerXXXVI (11960) Colour, Index, ,Sec- 0nd Edition, .1956, edited jointlybyvtheSocietybf; Dyers and1Golourists1.and;the; American-Association: of Textile Chemists and Colorists, compiles a: vast; amount: of; in: formation on-manyvof theuseful dyestulfsor prototypes ofi'these at the time ofpublication; relativeto. commercial names, manufacturers, chemicalj composition andhow made, ,ide'ntification 'by Cli numbers andrnarnes, andthe like. Dyes of-the;disperse:-typ e:andzof theazoictype. are preferred; since they; fully penetrate the-alloy fibers of :this; invention. Vat'dyes, .vat estendyes; and=sulfur dyes are less preferred, sincethese dyes penetrate the .fibers only superficially to: produce firing; dyeingszr."

Useful dyes of; the disperse type may. have anthraw quinone or az-o structures; and; are. characterized by an absence of highly ionizable sulfonic;.acid;or sulfonic. acid ester groups. Particularly preferred .dyes of-the; disperse type are those; which; are capable ofrforming-complexes with polyvalent-metal atoms, as for; example,;dyes having the, following structures: 1

In structural Formulas 4 to 8 inclusive, naphthalene rings may be substituted for the benzene rings shown. Suitable dyes may also have, permissibly, but not necessarily, one or more of the following substituent groups attached to the dye molecule: alkyl, hydroxyalkyl, alkoxyl, hydroxyl, nitro, halo, acetamido, or sulfonamido groups. For convenience, disperse dyes which form complexes with polyvalent metal atoms are herein termed disperse mordant dyes.

Azoic dyes are developed in situ in the alloy fibers of this invention by coupling of an azoic coupling component and a diazotized azoic diazo component under suitable conditions of application and development as hereinafter described. Suitable azoic coupling components and azoic diazo components for use in this invention must each be free of highly ionized substituent groups such as sulfonic acid, carboxylic acid, aminocarboxylic acid, halogen-oarboxylic acid, and esters and salts of such acids. Moreover, the azoic coupling component must be applied in the free phenol or enol form for effective absorption by the alloy fibers, and the azoic diazo component must be applied as the free amine for effective absorption by the alloy fibers. Additionally, the azoic diazo component must be diazotized in the fiber, and it is preferable to carry out the diazotization of the azoic diazo component in the presence of the azoic coupling component to promote optimum coupling and development of the resulting azoic dye within the fiber.

Substantially all azoic dyes have at least one characteristic -o=i7-N=N- group which is capable of forming complexes with polyvalent metal atoms under suitable conditions, and are therefore especially preferred for the purposes of this invention.

Vat dyes are dyed on the alloy fibers of this invention in the leuco or vat acid form acidified dye baths, and are subsequently oxidized by conventional methods to the vat dye.

The vat ester dyes listed in the Technical Manual of the AATCC are sulfuric acid esters of leuco vat dyestuffs of either the quinoid or indigoid type of vat dyestuffs. For

containing a reducing agent for these dyes which is effective in acid solution, such as sodium formaldehyde sulfoxylate, and are subsequently oxidized by conven tional methods to develop the oxidized form of the dye.

Selected sulfur dyes can be applied to polypropylene alloy fibers using a slightly modified dyeing procedure than that usually recommended for sulfur dyeing. The preferred sulfur dyes for the alloy fibers of this invention are applied from a mildly alkaline dyebath to which has been added a water soluble or dispersible reducing agent, such as thiourea dioxide, that has demonstrated effectiveness at a pH of 36. During the course of the dyeing cycle the pH is gradually adjusted with acids or buffers so that substantially half of the dyeing cycle is carried out at the boil at a pH between 4-6. The dyestuffs are finally fixed by oxidizing at slightly elevated temperatures in a mildly acid oxidizing bath.

It follows therefore that the particular dyeing procedure employed for dyeing the alloy fibers of this invention depends upon the type of dye selected. Methods for dyeing hydrophobic artificial fibers with any of the classes of dyes discussed hereinbefore are well known in the art, and are readily adapted for dyeing the alloy fibers of this invention, in the light of the preceding discussion of these dye classes in relation to the present invention. Following the dyeing, the dyed fibers are given a conventional hot soaping, and are then thoroughly rinsed and dried.

The general nature of the invention having been set forth, the following examples illustrate some specific embodiments of the invention. It is to be understood, however, that the invention is not limited to the examples, since the invention may be practiced by the use of various modifications and changes within the scope of the invention as described herein.

EXAMPLES 1-12 These examples compare dyeings made with representative disperse and azoic dyes on fabrics knitted from 210/35 continuous filament yarns of stereoregular polypropylene, and from similar 210/35 continuous filament yarns of alloys made from the same stereoregular polypropylene with copolymers of ethylene and vinyl acetate. The composition of these yarns follows:

Ingredients Example Designation and Composition (Parts by Weight) Stereoregular Polypropylene 72 Ethylene: 28 Vinyl Acetate Copolymer (by weight) 30 Vinyl Acetate Copolymer (by Ethylene' 67 Ethylene: 33 Vinyl Acetate Copolymer (by weight) weight)- 60 Ethylene: 40 Vinyl Acetate Copolymer (by Copolymer (by Bis(1- 2-11ydroxyethyl1-2-undecyl-2imidazoline) chromium acetate (containing 6.7% chromium). (l-[z-hydroxyethyl]-2-undecyl-2-imidazoline) chromium acetate (containing 11% chromium) Nickel salt of Di(2-hydroxy-5[1,1,3,3-tetramethylbutyl] phenyl) snlrnnp the purposes of this invention the sulfuric acid esters of leuco vat dyes of the indigoid type are preferred over the quinoid type, since in general these lead to more level dyeings. These vat ester dyes are dyed on the Each alloy composition employed in the above Examples 2 to 12 was prepared by dissolving the ethylene-vinyl acetate copolymer, and the chromiumor nickel complex (when one of these was used), in chloroform to make alloy fibers of this invention from acidified dye baths gabout 10% by weight solution of the copolymer inthe ehlor oforrn, spraying this solution uniformly on the stereoregular polypropylene flake, evaporated the chloroform, and then melt-extruding the thus coated polypropylene flake into strands which were chilled and chopped into uniform molding powder granules. Unalloyed stereoregular polypropylene flake employed in Example 1 was similarly melt-extruded and reduced to uniform molding powder granules.

These molding powders were then melt-spun into 210 denier/ 35 filament continuous filament yarns which were then knit on a standard tubular knitting machine into fabric specimens.

For dyeing, each fabric specimen was scoured at a 40 to 1 liquor to fabric ratio by weight in an aqueous bath containing 1% by weight of a nonionic alkylphenoxypoly- (ethyleneoxy) ethanol detergent (I'gepal C0630), and ad justed to a pH of with sodium carbonate, for 30 minutes at 160 F. The scoured fabric specimens were then well rinsed and kept damp for dyeing.

Dye baths for the disperse dyes were prepared by pasting an amount of disperse dye equal to 1% by weight, based on fabric weight, with an equal weight of Igepal C0630 in hot water. This paste concentrate was then added to the aqueous dyebath, also containing 1% Igepal C0630 by I 10 az oic diazo component dispersion and the az'oic coupling component solution to a distilledwater bath containing 4% by weight, based on fabric weight, of a 1:1 mixture by by holding under gentle agitation for 10 minutes at 120-,

The rinsed, damp fabric for each example was entered into its respective dye bath at a :1 dye liquor'to fabric ratio by weight at 120-130 F. and was worked in the dye liquor for approximately 10 minutes, after which the temperature of the dyebath was raised rapidly to the boil, and was held at the boil for 2 hours, with frequent working of the fabric.

The dyebath for each example was then drained from the dyed fabric specimen which was then well rinsed with warm water containing a small amount of Igepal C0630, and the fabric was given a hot soaping at about 160180 F. for approximately 30 minutes at a 40:1 liquor to fabric ratio by Weight in an aqueous bath eoritair'iing 1% by Weight, based on fabric weight, of Igepal CD630 and adjusted to a pH of 10 with sodium carbonate, followed by rinsing well with warm water and drying.

The dye components for each azoic dyeing were prepared as follows:

The azoic coupli-ngcomponent, in an amount equal to 0.75% by weight, based on fabric weight, was pasted with 10 parts by weight, based on azoic coupling component, of denatured ethyl alcohol and heated to approximately 46 C. with stirring. A solution of sodium hydroride/ water/denatured ethyl alcohol in a ratio of 16/ 100/ 100 parts by weight, equal to 10 times the weight of the azoic coupling'cornponent was added to the pasted azoic coupling component, warming the mixture to approximately 46 C. to dissolve the azoic coupling component, and the solution thus obtained was diluted with enough distilled water to double the volume.

A dispersion of the azoic diazo component was prepared by pastingan amount of the azoic diazo component equal to 0.75% by weight, based on fabric weight, with 10 parts by weight, based on Weight of azoic diazo component, of a 25% by weight solution of Igepal C0630 in water, and with. 5 parts by Weight, based on weight of azoic diazo component, of isopropanol, and heating to approximately 46C. with stirring. The dispersion of a'zoic diazo component was then diluted with enough'distilled waterto double the volume.

"Fach "azoic dye bath was then prepared by adding the .light resistance tests a scale of 0 to 5 was employed weight of polychlorinated benzenezalkyl substituted benzoic acid ester carrier, and 1.5% by weight, based on fabric weight, of the trisodium salt of ethylenediamine tetraacetic acid seqnestrant, and the liquor to fabric ratio was adjusted to 40 to 1 by weight of distilled water. The pH of each dye bath was between 11 and 12. Each water-wet fabric was then immersed in its respective dye bath, and the bath was raised to boiling in about 30 minutes and boiling was continued for 30 minutes, working the fabric frequently. The pH of the dye bath was then lowered to a pH value between 6 and 7 using an aqueous acetic acid solution containirig approximately 50% by weight of acetic acid. Boiling of the bath was continued for an additional 30 minutes, after which the bath was drained from the fabric, and the fabric was well rinsed with distilled water containing 0.5 by weight of Igepal C0630, based on fabric weight.

Each rinsed fabric from its respective azoic dye bath was then immersed at a liquor to fabric ratio of 40 to 1 at room temperature in an aqueous diazotizing and developing bath containing 8% by weight formic acid, 8% by weight sodium nitrite, and 1% by weight of Igepal C0630, each based on fabric weight, and kept at room temperature for 30 minutes. The temperature of the diazotizing bath was then raised 'to 50 C. and held at this temperature for an additional 30 minutes. The bath was then drained from the fabric, and the fabric was thoroughly rinsed, first with distilled water at room temperature and then with warm distilled water containing 0.5% by weight of Igepal C0630, based on fabric weight.

Each dyed fabric was then subjected to a hot soaping for 30 minutes at 70 C. ata 40 to 1 liquor to fabric ratio by weight in an aqueous bath containing 1% of Igepal C0630 and adjusted to a pH of 9 with sodium carbonate. The fabric was then thoroughly rinsed with distilled Water and dried. V

The dyed fabric specimens were compared visually for depth of shade, and were then subjected to AATCC Laundering Test Method 61-1957-111; AATCC Dry Cleaning Test Method -1960; and to AATCC Carbon-Arc Lamp Test Method 16A-1960 for 24 hour, 48 hour, and 72 hour periods of exposure, and compared. The above washing, dry cleaning, and carbon-arc lamp tests are described in the Technical Manualof the American Association of Textile Chemists and Colorists, volume XXXVI, 1960, Howes Publishing Co., Inc., 44 East 23rd St., New York.

For depth of shade the following rating scale was employed:

For the wash resistance, dry cleaning resistance, and

having the following significance:

5=no visible fading or loss of color. 4=very slight fading or loss of color.

3 :slight to medium fading or loss of color. 2=medium to severe fading or loss of color. l=very severe fading or loss of color. 0=complete loss of color.

The above scale of color fastness ratings is interpreted in terms of the International Gray Scale as described on page 78 of the previously referred to Technical Manual of the American Association of Textile Chemists and Colorists.

1 '1 Comparative date obtained for Examples 1-12 follow, Tables I and II: 1

o I a many dyeings in accordance with thisinvention an improvement in resistance to loss of color by' dry cleaning Table I Disperse DyeCelliton Disperse Dye-Celliton Fast Disperse Dye-Resolin Red Fast Pink RFCF Yellow 4 RL (General FB (13 ayer-Verona) (General Dyestuii) Dyestuii) Example Designation Dye Test Ratings Dye Test Ratings Dye Test Ratings Vertical Column (1) under each dyestuti shows ratings for Depth of Color obtained on dyeing. Vertical Column (2) under each dyestuti shows ratings for Color Fastness in AATCC Laundering Test Method 61-1957-III Vertical Column (3) under each dyestuii shows ratings for Color Fastness in AA'ICC Dry Cleaning Test Method 85-1960.

Vertical Columns (4), (5) and (6) under each dyestuil show ratings for Color Fastness, respectively, after 24 hours, 48 hours, and 72 hours in AATCC Carbon-Arc Lamp Test ISA-1960.

Table II Azoic Dye-C. I. Azoic Azoic DyeC.I.Azoic Cou- Coupling Component 12 pling Component 12 (C. I. Disperse Dye-Polydye Blue (C. I. 37550-Naphthol 37550-Naphthol AS-ITR) GSFR (Interchemical) AS-ITR) with C. I with C. I. Azoic Diazo AzoicDiazo Component Component (C. I. Example 42 (C. I. 37150-Red 37175-Blue Base BB) Designation Base ITR) Dye Test Ratings Dye Test Ratings Dye Test Ratings Vertical Column (1) under each dyestufi shows ratings for Depth of Color obtained on dyeing.

Vertical Column (2) under each dyestufi shows ratings for Color Fastness in AATCC Laundering Test Method 61-1957- III, Vertical Column (3) under each dyestuif shows ratings for Color Fastness in AATCC Dry Cleaning Test Method 85-1960.

Vertical Columns (4), (5) and (6) under each dyestuft show ratings for Color Fastness, respectively, after 24 hours, 48 hours, and 72 hours in AATCC Carbon-Arc Lamp Test USA-1960.

The foregoing description, with particular reference to immersion dyeing of the alloy fibers of this invention, is readily adaptable to commercial machinery and techniques for kier, package and rope dyeing, and to continuous dyeing by padding and jig procedures Moreover, practice of this invention contemplates the use in any of the dyebaths of various conventional dyebath assistants and auxiliaries, such as emulsifying agents, wetting agents, carriers, sequestrants, swelling agents, developers, protective colloids, stabilizers, and the like, in amounts commonly employed in the art of dyeing hydrophobic fibers. Surface active agents, preferably nonionic types, such as alkylphenoxypoly(ethylenoxy) ethanol or polyoxyalkylated alkyl phenols, developers such as diethyltartrate or diethylethanolamine, and carries such as polychlorinated benzene, alkyl or aryl substituted benzoic acid esters, and the like, are particularly desirable in preferred practice of this invention.

From the foregoing description it will be apparent that this invention accomplishes the objectives sought, and provides filamentary material of stereoregular polypropylene which can be dyed to deep shades with materially improved resistance to fading upon exposure to light. In

fluids is also obtained. The invention, described hereinabove with particular reference to alloy compositions of stereoregnlar polypropylene in the form of filamentary material, also contemplates alloy compositions of stereoregular polypropylene in other forms, such as films, foils, expanded foams, and the like, and the dyeing of such other forms in accordance with this invention.

It is further apparent from the foregoing description that many modifications of this invention can be made Without departing from the scope thereof, with only such limitations placed thereon as are imposed by the appended claims.

What I claim and desire to protect by Letters Patent is:

l. Artificial fibers of improved dyeability consisting essentially of a uniform admixture of stereoregular polypropylene and from about 1% to about 25% by weight of said admixture of a copolymer of ethylene and an ethylenically unsaturated ester of a saturated fatty acid.

2. Artificial fibers in accordance with claim 1 in which I said copolymer has a weight ratio of ethylene to ethyl- 3. Artificial fibers in accordance with claim 2 in which said copolymer is a copolymer of ethylene and vinyl acetate.

4. Artificial fibers in accordance with claim 1 in which said uniform admixture also contains from about 0.01% to about 5% by Weight of said polypropylene of a polyvalent metal in the form of polyvalent metal compound.

5. Artificial fibers in accordance with claim 4 in which said polyvalent metal compound is a nickel compound.

6. Artificial fibers in accordance with claim 4 in which said polyvalent metal compound is a chromium compound.

7. A process for improving the dyeability of stereoreg-.

ular polypropylene filamentary material which comprises preparing an alloy of 'stereoregular polypropylene with from about 1% to about 25% by weight of said alloy of a copolymer of ethylene and an ethylenically unsaturated ester of a saturated fatty acid, forming the alloy into filamentary material, and dyeing the filamentary material.

8. A process in accordance with claim 7 in which said copolymer has a Weight ratio of ethylene to unsaturated ester of saturatedfatty acid between about 15:85 and about 85:15.

9. A process in accordance with claim 8 in which said copolymer is a copolymer of ethylene and vinyl acetate.

10. A process for improving the dyeability of stereoregular polypropylene filamentary material which comprises preparing an alloy of stereoregularpolyproplene with from about 1% to about 25% by weight of said alloy of a copolymer of ethylene and an ethylenically unsaturated ester of a saturated fatty acid, and with from about 0.01% to about 5% by weight of said polypropyl- "i4 ene of a polyvalent metal in the form of a polyvalent metal compound, forming the alloy into filamentary material, and dyeing the filamentary material With a dye which is capable of forming complexes with polyvalent ture of a copolymer of ethylene and an ethylenically un-' saturated ester of a saturated fatty acid.

References Cited by the Examiner UNITED STATES PATENTS 2,200,429 5/40 Perrin et al 26097.3 X 2,394,960 2/4 6 Young 260-867 2,395,381 2/46 Squires 260-873 2,703,794 3/55 Roedel 260-873 FOREIGN PATENTS 5/57 Australia.

NORMAN G. TORCHIN, Primary Examiner.

Caldwell et al.

Alsys 260-897 X EW H UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,163,492 December 29, 1964 Walter W. Thomas It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 15, for "to trade" read to the trade line 19, for "posses" read possess line 36, for "other materials" read other fiber materials same column 1, line 42, for "shades only" read shades with only column 7, line -39, for "form acidified" read from acidified column 9, line 2, for "evaporated" read evaporating column 11, line 1, for "date" read data columns ll and 12,

Table I, under the column heading "Disperse Dye-Resolin Red FB (Bayer-Verona)" column (4), opposite "Example Designation 12'', for "4-" read 4+ Table II, under the heading "Azoic Dye- C. I. Azoic Coupling Component 12 (C. I; 37-550-Naphthol AS- ITR) with C. I. Azoic Diazo Component 20 (C; I. v357l75-Blue Base BB)" column (5), opposite "Example Designation 1", for "2" read 3 column 11, line 67, for "carries" read carriers Signed and sealed this 11th day of May 1965.

( E Attest:

ERNEST W. SWIDER EDWARD J,. BRENNER Attesting Officer Commissioner of Patents Notice of Adverse Decision in Interference In Interference No. 95,391 involving Patent No. 3,163,492, W. V. Thomas, POLYPROPYLENE COMPOSITIONS OF IMPROVED DYEABILITY AND PROCESS OF DYEING, final judgment adverse to the patentee was rendered. Apr. 25, 1968, as to claims 1-3, 7 9, and 13.

[Ofiicial Gazette September 94, 1.968.] 

7. A PROCESS FOR IMPROVING THE DYABILITY OF STEROOREGULAR POLYPROPYLENE FILAMENTARY MATERIAL WHICH COMPRISES PREPARING AN ALLOY OF STEROREGULAR POLYPROPYLENE WITH FROM ABOUT 1% TO ABOUT 25% WEIGHT OF SAID ALLOY OF A COPOLYMER OF ETHYLENE AND ETHYLENICALLY UNSATURATED ESTER OF A SATURATED FATTY ACID, FORMING THE ALLOY INTO FILAMENTARY MATERIAL, AND DYEING THE FILAMENTARY MATERIAL. 